1. Field of the Invention
The present invention relates to a data recording and reproducing apparatus for recording and reproducing data in and from a digital data recording medium such as a hard disk and an optical disk.
2. Description of the Related Art
In a data recording/reproducing apparatus utilizing a disk-like recording medium, such as a hard disk device (HDD) and an optical disk device, there is provided a recording area formed of a plurality of concentrically circular tracks on a disk surface. Each track (recording area for one cycle) is divided into plural sectors. In such an HDD, in order to provide higher recording density, it is necessary to reduce the width of each track and to reduce an interval between tracks.
However, in order to avoid influence of crosstalk between adjacent tracks, usually, a non-recording area, i.e. a guard band are provided between the tracks. As the area of the guard band is narrower, the track density can be higher, thereby making it possible to improve recording density. Nevertheless, if accuracy of tracking control, for positioning a head on a target track is low, it is necessary to widen the area of the guard band. As mentioned above, as to the area of the guard band, a requirement of the recording density disagrees with a requirement of the tracking control accuracy. Moreover, it is necessary for higher recording density to narrow the tracking width, but in an optical disk device, in order to avoid influence of crosstalk, it is impossible to reduce a track pitch further than optical resolution.
In a recording and reproducing apparatus using a medium other than a disk recording medium, such as in a video tape recorder (VTR), since azimuth angles of adjacent tracks are different so that the azimuth effect can be utilized, the influence of crosstalk caused by the adjacent tracks is reduced. As a result, guard bands between adjacent tracks are not required.
However, such an azimuth recording system requires a special recording and reproducing head. Furthermore, the azimuth recording system has disadvantages such that crosstalk elimination performance of a low-frequency component is low and as the track width becomes narrower, the crosstalk elimination performance is deteriorated worse.
Therefore, it is impossible for a prior data recording and reproducing apparatus to attain higher recording density without influence of crosstalk.